1. Field of the Invention
This invention relates generally to an image sensing and processing apparatus and, more particularly, to an electronic image sensing and processing apparatus for providing an enhanced electrical output signal.
2. Description of the Prior Art
Electronic image scanning and processing apparatus embodying a charge transfer type of scanning device such as a CCD fabricated in the form of an integrated circuit on a thin silicon semiconductor substrate are well known in the art.
It is also well known to utilize such apparatus to scan a subject such as a color negative or transparency or a positive or a document and process the information derived therefrom to provide a facsimile of the subject in enhanced or corrected colors. Such apparatus sense the subject and introduce a color correction factor so that each color has a predetermined density and displays the subject with a corrected color as disclosed in U.S. Pat. No. 3,644,664, entitled "Correction Level Adjustment for Video Negative Analyzer", by Robert Huboi et al., issued Feb. 22, 1972. Huboi et al. recognized that prior art color analyzing and correction devices were deficient in not taking into account the effect that one color may have on another color in determining the degree of color correction that should be imparted to the image. Toward that end well-known color correction equations are utilized in which each red, green and blue primary color is corrected as a function of all three primary colors. As is readily apparent, in order to provide such color correction it is necessary that the red, green and blue color signals be available at all times despite the fact that the subject is generally scanned through red, green and blue light filter elements with each filter element moved in sequence over the light sensing device. Huboi et al. manages to provide continuous red, green and blue color separation signals through complex circuitry that continuously determines each color separation signal as a function of the other color scanned during those intervals in which that color is not directly scanned. Continuous red, green and blue color separation signals can also be provided during the sequential red, green and blue color filter scan of the subject by storing in image memory those color signal components scanned through the immediately preceding color filter in the sequence. Such image memories, however, must have large storage capacities in order to accommodate the large volume of image data that must be stored for each of the two primary colors not being immediately scanned. This memory storage capacity requirement must be even further increased when the electronic image data is converted from an analog format to a digital format in order to provide a high quality facsimile of the subject.
Therefore, it is a primary object of this invention to provide an electronic image sensing and processing apparatus in which the red, green and blue color separation signals are each enhanced as a function of the other color separation signals utilizing a minimum storage capacity memory.
It is a further object of this invention to provide an electronic image sensing and processing apparatus in which the primary red, green and blue color separation signals are sensed in high resolution and the cyan, magenta and yellow color separation signals are sensed in low resolution to provide full color correction or enhancement utilizing a minimum capacity image memory to store the low resolution cyan, magenta and yellow color separation signals.
Other objects of the invention will be in part obvious and will in part appear hereinafter. The invention accordingly comprises a mechanism and system possessing a construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.